The present invention relates to data storage systems, and more particularly, this invention relates to multi-layer magnetic nanoparticles, which may be especially suited for use in magnetic recording media.
In magnetic storage systems, magnetic transducers read data from and write data onto magnetic recording media. Data is written on the magnetic recording media by moving a magnetic recording transducer to a position over the media where the data is to be stored. The magnetic recording transducer then generates a magnetic field, which encodes the data into the magnetic media. Data is read from the media by similarly positioning the magnetic read transducer and then sensing the magnetic field of the magnetic media. Read and write operations may be independently synchronized with the movement of the media to ensure that the data can be read from and written to the desired location on the media.
An important and continuing goal in the data storage industry is that of increasing the density of data stored on a magnetic medium. For tape storage systems, this goal has led to an increase in the track and linear bit density on recording tape, and a decrease in the thickness of the magnetic tape medium.
One approach to achieve higher recording densities in magnetic media is to reduce the size of the recording bits, which typically necessitates the design of smaller and smaller components. However, miniaturization of the recoding bits and components associated therewith, while effective, presents several challenges. For instance, as the magnetic particles in a magnetic recording layer become smaller and smaller, the magnetic particles may become thermally unstable, such that thermal fluctuations result in magnetization reversal and the loss of recorded data. Increasing the magnetic anisotropy of the magnetic particles may improve the thermal stability thereof; however, an increase in the magnetic anisotropy requires an increase in the switching field needed to switch the magnetization of the magnetic particles during a write operation. Thus, the trilemma associated with magnetic recording relates to the difficulty in: (1) increasing the media signal to noise ratio (SNR); (2) maintaining media thermal stability; and (3) maintaining media write-ability.